SUMMARY OF PROPOSAL 51069

OBSERVATION OF CYGNUS X-3 IN ITS LOW STATE

ABSTRACT

Cygnus X-3 exhibits a ''High State'' and a ''Low State''. The two states are differ widely in the continuum spectra and in the properties of iron line. The previous ASCA observations were taken only in its ''High State'', and revealed emission lines from various elements and emission-line-like feature produced by free-bound transition for S XVI. The plasma producing these spectral features is influenced by the luminosity and energy spectrum of a central source and plasma density. To understand two different intensity state transition, it is important to study the relations between a central source and the surrounding plasma. This study is enabled by sperior energy resolution of ASCA.